package main

import (
	_ "github.com/go-sql-driver/mysql"
	"database/sql"
	"fmt"
)

func main() {
	db, err := sql.Open("mysql", "username:[email protected](127.0.0.1:3306)/db?charset=utf8")
	checkErr(err)

	defer db.Close()

	uname := "username"

	// query
	stmt, err := db.Prepare("SELECT USER_NAME, `PASSWORD` FROM db.TAPP_USER WHERE USER_NAME = ?")
	checkErr(err)
	rows, err := stmt.Query(uname)
	checkErr(err)

	for rows.Next() {
		var username string
		var password string
		err = rows.Scan(&username, &password)
		checkErr(err)
		fmt.Println(username)
		fmt.Println(password)
	}

	// update
	newPwd := "newUserPwd"
	stmt, err = db.Prepare("UPDATE db.TAPP_USER SET `PASSWORD` = ? WHERE USER_NAME = ?")
	checkErr(err)

	res, err := stmt.Exec(newPwd, uname)
	checkErr(err)

	affect, err := res.RowsAffected()
	checkErr(err)

	fmt.Println(affect)

	// query
	stmt, err = db.Prepare("SELECT USER_NAME, `PASSWORD` FROM db.TAPP_USER WHERE USER_NAME = ?")
	checkErr(err)
	rows, err = stmt.Query(uname)
	checkErr(err)

	for rows.Next() {
		var username string
		var password string
		err = rows.Scan(&username, &password)
		checkErr(err)
		fmt.Println(username)
		fmt.Println(password)
	}
}

func checkErr(err error) {
	if err != nil {
		fmt.Println(err.Error())
	}
}